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1 Water is pumped from the holding tank through two activated carbon polishing vessels The piping between the two vessels is designed to allow either carbon vessel to be used as the primary adsorber The piping also allows either carbon vessel to be bypassed during maintenance A pressure switch is used downstream of a pressure reducing valve to protect the carbon vessels from being over-pressurized. Water passes from the carbon vessels to a holding tank The head space of this tank is continuously monitored for the presence of hydrocarbon vapors by a lower explosive limit monitor If hydrocarbon vapors are detected above i ppmv in the headspace of this tank, a motor actuated ball valve is closed, stopping the discharge of water to the storm drain and the GETS system is shut down. The entire treatment system is secondarily contained by a concrete pad with a 6-inch high ' berm around its perimeter. A high level switch is located within the bermed area and will shut down the GETS if a high level is detected. A pump located in the containment pad sump twill transfer any water captured by the pad to the treatment system 5 . GROUNDWATER EXTRACTION AND TREATMENT SYSTEM ' SAFEGUARDS The Process and Instrumentation Diagram depicts all the safeguards designed to monitor the GETS and to shut it down in the event of a malfunction The logic governing the operation of the safeguards is shown in the Logic Diagrams drawing Shutdown of the GETS is controlled by a system trip control bus This trip control bus shuts down all pumps, the air stripper blower, and the ultraviolet sterilizer, closes the motor-actuated butterfly valve between the air stripper and the catalytic oxidizer, and notifies the system operator by telemetry that a shutdown has occurred The system trip control bus is activated by any one or combination of the following catalytic oxidizer shutdown, high level detected at any high level switch, low level detected at low level switch, high pressure detected at high pressure ' switches, loss of vacuum detected by pressure/vacuum switch, foss of flow for more than one hour detected by flow switch, flow detected from the catalytic oxidizer to the air stripper by flow switch, or detection of hydrocarbon vapors in the LEL tank by the lower explosive limit detector In addition to the above safeguards, in the event of reduction, loss, or failure of electrical power, the GETS is automatically shut down and an operator is required to restart the system Any time the system is shut down, the system operator is notified by telemetry 6 . CONTROL OF ACCIDENTAL LOSSES OR DISCHARGES ' Thep revention of accidental discharge starts at each wellhead. The wellhead is contained in a � scaled Christy Box Within the Christy Box the tubing from the submersible pump is 4 m�ar3yaa.�--